A skateboarder on a half-pipe changes his velocity from 6.0 m/s forwards to 4.0 m/s backward in 5.0 s. What is the acceleration of the skateboarder?

A cross country skier can complete a 7.5 km race in 45 minutes. What is the skiers's average speed

Which type of mechanical wave needs a source of energy to produce it? a. a transverse wave b. a longitudinal wave c. a surface wave d. all of the above

A stunt car with a mass of 1,000 kilograms crashes into a tree on a movie set. During the collision, the acceleration of the car was 3 meters/second2. What was the force of impact of the collision on the car?

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When you flick a coin so that it slides across a table, what four forces are acting on the coin?

A student examining a joint observes collagen-rich connective tissue fibers linking the bones, but finds no synovial cavity. Which structural classification fits the observed joint?

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Tarzan runs at 6 m/s and grabs a vertical vine (negligible mass) 4.1 m long which is tied to a tree at the top. Tarzan swings up. Determine the maximum height Tarzan will swing up and the angle the vine makes respect to vertical.

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What is the change in internal energy if 60 J of heat are added to a system and the system does 40 J of work on its surroundings? Use AU = Q-W.